621 research outputs found
THE PREDICTIVE MODEL OF INTERVAL TIME BASED ON PACING STRATEGY IN A 400 M HURDLES RACE
The purpose of the present study was to verify the reliability of the prediction equation for interval time (the times between hurdles) established from the hierarchical model in the 400 m hurdles. From 155 data samples of previous studies (record range: 47.42–50.99s), regression equations were established to predict each interval time throughout the race (model #1), during the first and latter halves (model #2) and during the first, middle, and last parts (model #3). Leave-one-out cross-validation was used to avoid overtraining for each regression equation. Models #2 and #3 showed better goodness of fit and generalization for each interval time compared to model #1. These hierarchical models are found to be more reliable compared to the non-hierarchical model. The hierarchical model will help to set the pace distribution to achieve the athlete’s target records accurately
Effect of Dy substitution in the giant magnetocaloric properties of HoB
Recently, a massive magnetocaloric effect near the liquefaction temperature
of hydrogen has been reported in the ferromagnetic material HoB. Here we
investigate the effects of Dy substitution in the magnetocaloric properties of
HoDyB alloys ( = 0, 0.3, 0.5, 0.7, 1.0). We
find that the Curie temperature () gradually increases upon
Dy substitution, while the magnitude of the magnetic entropy change || at = decreases from 0.35 to 0.15
J cm K for a field change of 5 T. Due to the presence of two
magnetic transitions in these alloys, despite the change in the peak magnitude
of ||, the refrigerant capacity () and
refrigerant cooling power () remains almost constant in all
doping range, which as large as 5.5 J cm and 7.0 J cm for a field
change of 5 T. These results imply that this series of alloys could be an
exciting candidate for magnetic refrigeration in the temperature range between
10-50 K.Comment: 19 pages, 5 figures, 2 table
Evaluation of the effect of oral appliance treatment on upper-airway ventilation conditions in obstructive sleep apnea using computational fluid dynamics
Objective: To evaluate the effect of oral appliance (OA) treatment on upper-airway ventilation conditions in patients with obstructive sleep apnea (OSA) using computational fluid dynamics (CFD).
Methods: Fifteen patients received OA treatment and underwent polysomnography (PSG) and computed tomography (CT). CT data were used to reconstruct three-dimensional models of nasal and pharyngeal airways. Airflow velocity and airway pressure measurements at inspiration were simulated using CFD.
Results: The apnea–hypopnea index (AHI) improved from 23.1 to 10.1 events/h after OA treatment. On CFD analysis, airflow velocity decreased at the retropalatal and epiglottis-tip levels, while airway pressure decreased at the retropalatal, uvular- and epiglottis-tip levels. The AHI of patients with OSA before OA treatment was correlated with airway pressure at the epiglottis-tip level.
Discussion: Treatment with OA improved the ventilation conditions of the pharyngeal airway and AHI. Results of CFD analysis of airway pressure and airflow velocity helped determine the severity and ventilatory impairment site of OSA, respectively
Towards Robust Plant Disease Diagnosis with Hard-sample Re-mining Strategy
With rich annotation information, object detection-based automated plant
disease diagnosis systems (e.g., YOLO-based systems) often provide advantages
over classification-based systems (e.g., EfficientNet-based), such as the
ability to detect disease locations and superior classification performance.
One drawback of these detection systems is dealing with unannotated healthy
data with no real symptoms present. In practice, healthy plant data appear to
be very similar to many disease data. Thus, those models often produce
mis-detected boxes on healthy images. In addition, labeling new data for
detection models is typically time-consuming. Hard-sample mining (HSM) is a
common technique for re-training a model by using the mis-detected boxes as new
training samples. However, blindly selecting an arbitrary amount of hard-sample
for re-training will result in the degradation of diagnostic performance for
other diseases due to the high similarity between disease and healthy data. In
this paper, we propose a simple but effective training strategy called
hard-sample re-mining (HSReM), which is designed to enhance the diagnostic
performance of healthy data and simultaneously improve the performance of
disease data by strategically selecting hard-sample training images at an
appropriate level. Experiments based on two practical in-field eight-class
cucumber and ten-class tomato datasets (42.7K and 35.6K images) show that our
HSReM training strategy leads to a substantial improvement in the overall
diagnostic performance on large-scale unseen data. Specifically, the object
detection model trained using the HSReM strategy not only achieved superior
results as compared to the classification-based state-of-the-art
EfficientNetV2-Large model and the original object detection model, but also
outperformed the model using the HSM strategy
Necessity for Reassessment of Patients with Serogroup 2 Hepatitis C Virus (HCV) and Undetectable Serum HCV RNA
We encountered a patient positive for anti-hepatitis C virus (HCV) whose serum HCV RNA was undetectable with the Roche AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM) version 1 but showed a high viral load with the Abbott RealTime HCV assay (ART). Discrepancies in the detectability of serum HCV RNA were investigated among 891 consecutive patients who were positive for anti-HCV. Specific nucleotide variations causing the undetectability of HCV RNA were determined and confirmed by synthesizing RNA coding those variations. Serum samples with the discrepancies were also reassessed by CAP/CTM version 2. Among the 891 anti-HCV-positive patients, 4 patients had serum HCV RNA levels that were undetectable by CAP/CTM version 1 despite having levels of > 5 log IU/ml that were detected by ART. All four patients had HCV genotype 2a and high titers of anti-HCV. Sequencing of the HCV 5' noncoding regions revealed 2 common variations, A at nucleotide (nt) 145 and T at nt 151. Synthesized RNAs of the HCV 5' noncoding region with standard (NCR145G151C) and variant nucleotides at nt 145 and nt 151 were quantified with CAP/CTM. RNAs of NCR145G151C and NCR145G151T were quantifiable with CAP/CTM version 1, while those of NCR145A151T and NCR145A151C went undetected. The substitution from G to A at nt 145 specifically conferred this undetectability, while this undetectability was reverted in synthesized HCV RNA with correction of this variation. Reassessment of these samples by CAP/CTM version 2 resulted in similar levels of HCV RNA being detected by ART. We conclude that HCV patients with undetectable HCV RNA by CAP/CTM version 1 should be reassessed for viral quantification
Contribution of histone N-terminal tails to the structure and stability of nucleosomes
AbstractHistones are the protein components of the nucleosome, which forms the basic architecture of eukaryotic chromatin. Histones H2A, H2B, H3, and H4 are composed of two common regions, the “histone fold” and the “histone tail”. Many efforts have been focused on the mechanisms by which the post-translational modifications of histone tails regulate the higher-order chromatin architecture. On the other hand, previous biochemical studies have suggested that histone tails also affect the structure and stability of the nucleosome core particle itself. However, the precise contributions of each histone tail are unclear. In the present study, we determined the crystal structures of four mutant nucleosomes, in which one of the four histones, H2A, H2B, H3, or H4, lacked the N-terminal tail. We found that the deletion of the H2B or H3 N-terminal tail affected histone–DNA interactions and substantially decreased nucleosome stability. These findings provide important information for understanding the complex roles of histone tails in regulating chromatin structure
Pregabalin- and azithromycin-induced rhabdomyolysis with purpura: An unrecognized interaction: A case report
AbstractIntroductionRhabdomyolysis associated with the use of pregabalin or azithromycin has been demonstrated to be a rare but potentially life-threatening adverse event. Here, we report an extremely rare case of rhabdomyolysis with purpura in a patient who had used pregabalin and azithromycin.Presentation of caseWe present the case of a 75-year-old woman with a history of fibromyalgia who was admitted with mild limb weakness and lower abdominal purpura. She was prescribed pregabalin (75mg, twice daily) for almost 3 months to treat chronic back pain. Her medical history revealed that 3days before admission, she began experiencing acute bronchitis and was treated with a single dose of azithromycin (500mg). She had developed rapid onset severe myalgia, mild whole body edema, muscle weakness leading to gait instability, abdominal purpura and tender purpura on the lower extremities. Laboratory values included a white blood cell count of 25,400/mL and a creatinine phosphokinase (CPK) concentration of 1250 IU/L. Based on these findings and the patient’s clinical history, a diagnosis of pregabalin- and azithromycin-induced rhabdomyolysis was made.DiscussionThe long-term use of pregabalin and the initiation azithromycin therapy followed by a rapid onset of rhabdomyolysis is indicative of a drug interaction between pregabalin and azithromycin.ConclusionWe report an extremely rare case of rhabdomyolysis with purpura caused by a drug interaction between pregabalin and azithromycin. However, the mechanisms of the interactions between azithromycin on the pregabalin are still unknown
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